1. Field of the Invention
The invention relates to a digital broadcasting receiving apparatus which can be applied to a receiving apparatus of a toll broadcasting such as a digital satellite broadcasting or the like.
2. Description of the Related Art
In recent years, a digital broadcasting system for transmitting multimedia data such as image signal, audio signal, and the like by using a communicating satellite has been being put into practical use. The present invention can be applied to a receiving apparatus of such as a digital broadcasting system. In FIG. 1, reference numeral 1 denotes a whole conventional receiving apparatus of a digital satellite broadcasting.
In FIG. 1, a receiving antenna 2 receives a radio wave from a communicating satellite (or broadcasting satellite). A converter annexed to the antenna 2 down-converts a reception signal to an IF (intermediate frequency) signal of a predetermined frequency and outputs the converted signal to a front-end 3. Although not shown, the front-end 3 is constructed by a tuner, a demodulating circuit, and an error correcting circuit. A desired transponder is selected by the tuner in the front-end 3. A signal from the selected transponder is QPSK (Quadrature Phase Shift Keying) demodulated by the demodulating circuit and is, further, error correction processed by the error correcting circuit, so that a transport stream output is derived. The error corrected output (transport stream) is supplied to a descrambling unit 4. A descrambling process for cancelling the scramble is performed in the descrambling unit 4.
A transport stream of MPEG2 (Moving Picture Experts Group) is obtained as an output of the descrambling unit 4 and is supplied to a demultiplexer 5. In the demultiplexer 5, a packet of a desired program is separated from the transport stream and video data, audio data, and control data are separated on the basis of information in a header portion. A memory 6 is provided so as to be used for a process of the demultiplexer.
The video/audio data from the demultiplexer 5 is decoded by an audio/video decoding unit (A/V decoder) 7 and reception video/audio signals are formed. The A/V decoder 7 is a decoder of MPEG2 and a memory 8 is provided in association with a process of the A/V decoder 7. The decoded video/audio signals are converted into analog video/audio signals by a D/A converter 9 and are outputted. An output video signal is supplied to a display and a reception video image is displayed. The output audio signal is amplified by, for example, an amplifier and is reproduced by a speaker.
The control data separated by the demultiplexer 5 is supplied to a CPU 10 serving as an equipment control unit. A memory 11 is provided in association with the CPU 10. Further, an interface unit 12 is connected to the CPU 10. A remote control signal receiving unit 13, a front panel 14 equipped with operation keys and the like, and an IC card (security module) 15 are connected to the CPU 10 through the interface unit 12. The CPU 10 reads out programs from the memory 11 and controls the operation of the receiving apparatus. The CPU 10 executes the control of the front-end 3, descrambling unit 4, demultiplexer 5, and an A/V decoder 7, reception of commands from the remote control signal receiving unit 13, display on the front panel 14, and reception of the button. As mentioned above, the CPU executes the control of the receiving apparatus.
A modem 16 is connected through the interface unit 12. The modem 16 and a modular jack 17 are connected. The modular jack 17 is provided on the rear panel of the receiving apparatus 1. The modular jack 17 and a telephone line service entrance 18 are connected by a cable. The modem 16 is used to transmit viewer information (accounting information and the like) stored in the IC card 15 through a telephone line. That is, monitor history information such as an accumulated amount of money and the like in the case where the viewer monitors a pay-per-view program is stored in the IC card 15. When the accumulated money amount reaches a preset upper limit value or periodically, the monitor history information which is read out from the IC card 15 is transmitted to a management system via the modem 16.
Ordinarily, at home, in many cases, there is one service entrance of the telephone line and the service entrance is away from the installing location of the receiving apparatus of the foregoing digital satellite broadcasting. It is, therefore, necessary to place an extension cable and to connect the modular jack 17 of the receiving apparatus and the service entrance 18. In the case where, on the other hand, there is a service entrance at the first floor of a home and the user wants to install the receiving apparatus on the second floor, since the extension cable becomes too long, it is necessary to perform a construction to install one more telephone line service entrance on the wall of the second floor.